Quantum defogging: temporal photon number fluctuation correlation in time-variant fog scattering medium

The conventional McCartney model simplifies fog as a scattering medium with space-time invariance, as the time-variant nature of fog is a pure noise for classical optical imaging. In this letter, an opposite finding to traditional idea is reported. The time parameter is incorporated into the McCartney model to account for photon number fluctuation introduced by time-variant fog. We demonstrated that the randomness of ambient photons in the time domain results in the absence of a stable correlation, while the scattering photons are the opposite. This difference can be measured by photon number fluctuation correlation when two conditions are met. A defogging image is reconstructed from the target's information carried by scattering light. Thus, the noise introduced by time-variant fog is eliminated by itself. Distinguishable images can be obtained even when the target is indistinguishable by conventional cameras, providing a prerequisite for subsequent high-level computer vision tasks.Comment: 6 pages, 9 figure

Quantum image rain removal: second-order photon number fluctuation correlations in the time domain

Falling raindrops are usually considered purely negative factors for traditional optical imaging because they generate not only rain streaks but also rain fog, resulting in a decrease in the visual quality of images. However, this work demonstrates that the image degradation caused by falling raindrops can be eliminated by the raindrops themselves. The temporal second-order correlation properties of the photon number fluctuation introduced by falling raindrops has a remarkable attribute: the rain streak photons and rain fog photons result in the absence of a stable second-order photon number correlation, while this stable correlation exists for photons that do not interact with raindrops. This fundamental difference indicates that the noise caused by falling raindrops can be eliminated by measuring the second-order photon number fluctuation correlation in the time domain. The simulation and experimental results demonstrate that the rain removal effect of this method is even better than that of deep learning methods when the integration time of each measurement event is short. This high-efficient quantum rain removal method can be used independently or integrated into deep learning algorithms to provide front-end processing and high-quality materials for deep learning.Comment: 5 pages, 7 figure

MLCopilot: Unleashing the Power of Large Language Models in Solving Machine Learning Tasks

The field of machine learning (ML) has gained widespread adoption, leading to a significant demand for adapting ML to specific scenarios, which is yet expensive and non-trivial. The predominant approaches towards the automation of solving ML tasks (e.g., AutoML) are often time consuming and hard to understand for human developers. In contrast, though human engineers have the incredible ability to understand tasks and reason about solutions, their experience and knowledge are often sparse and difficult to utilize by quantitative approaches. In this paper, we aim to bridge the gap between machine intelligence and human knowledge by introducing a novel framework MLCopilot, which leverages the state-of-the-art LLMs to develop ML solutions for novel tasks. We showcase the possibility of extending the capability of LLMs to comprehend structured inputs and perform thorough reasoning for solving novel ML tasks. And we find that, after some dedicated design, the LLM can (i) observe from the existing experiences of ML tasks and (ii) reason effectively to deliver promising results for new tasks. The solution generated can be used directly to achieve high levels of competitiveness

Indications of Universal Excess Fluctuations in Nonequilibrium Systems

The fluctuation in electric current in nonequilibrium steady states is investigated by molecular dynamics simulation of macroscopically uniform conductors. At low frequencies, appropriate decomposition of the spectral intensity of current into thermal and excess fluctuations provides a simple picture of excess fluctuations behaving as shot noise. This indicates that the fluctuation-dissipation relation may be violated in a universal manner by the appearance of shot noise for a wide range of systems with particle or momentum transport.Comment: 4 pages, 4 figures; title changed, major revision; to appear in J. Phys. Soc. Jp

A new route to achieve high strength and high ductility compositions in Cr-Co-Ni-based medium-entropy alloys: A predictive model connecting theoretical calculations and experimental measurements

新規高強度高延性合金の開発に成功 --計算と実験の融合による合金設計法の確立--. 京都大学プレスリリース. 2023-05-25.A new route to achieve high strength and high ductility compositions in the Cr-Co-Ni medium entropy alloys (MEAs) is proposed, by controlling the solid solution hardening parameter (Mean Square Atomic Displacement, MSAD) and twinning propensity parameter (Stacking Fault Energy, SFE), respectively. The MSAD is calculated to increase with the increase in the Cr content and with the increase in the Ni/Co ratio at high Cr concentrations, while the SFE is calculated to decrease with the increase in the Cr content and with the increase in the Co/Ni ratio at high Cr concentrations. In experiment, the strength at 0 K (derived from the temperature dependence of yield stress) increases as the Cr content increases and/or as the Ni content increases for a given high Cr content, so that a linear correlation is found between the yield strength at 0 K and MSAD. The SFE also decreases as the Cr content increases and as the Co content increases for a given high Cr content. However, while the tensile elongation increases with the decrease in SFE down to SFE values of 10–12 mJ/m2, it abruptly decreases once the SFE decreases below this value due to a change in major deformation mode from deformation twinning to deformation-induced ε-martensite transformation. Based on the established connection between the theoretical calculation and experimental measurement, outstanding combinations of strength and ductility are predicted and experimentally confirmed at high Cr compositions and at a bit Ni-rich side of the Co/Ni equi-composition line. The proposed composition (around 45Cr-20Co-35Ni) exhibits a greater 0 K strength and a superior 77 K tensile ductility by 32 % and 13 %, respectively, compared to those of the equiatomic Cr-Co-Ni alloy